The etiology of a variety of cancers has been pursued, oftentimes using multidisciplinary approaches. A major emphasis has been on investigating the etiology of female cancers, with substantial efforts expended on defining the role of the human papillomaviruses in several anogenital cancers (cervix, vulva, penis). Several natural history studies are underway which incorporate methodologic adjuncts to address problems inherent in many previous investigations. Also actively pursued has been the relationship of both endogenous and exogenous hormonal factors to several cancers. Of particular interest have been the effects of oral contraceptive use on the risk of premenopausal breast cancer and of combined estrogen/progestin therapy on cancers of the breast and endometrium. Attempts are also underway to assess risk factors for several relatively unstudied cancer sites, including cancers of the vagina, penis, and nasopharynx. Further efforts are being expended to clarify relationships of drinking water contaminants to a variety of cancers, pesticide exposures to risk of leukemia and non-Hodgkin's lymphoma, and therapy for rheumatoid arthritis to risk of subsequent hematopoietic cancers. A large study of multiple myeloma and cancers of the prostate, pancreas, and esophagus was completed and analyses are underway to assess reasons why these cancers occur more commonly in blacks than whites. Finally, analyses have been undertaken to examine the influence of gender and race on the incidence of cancers of the cervix, bladder, and lung.